UCA/ITA

AUA – American Underground Construction AssociationJohn Reilly was President, from 1999-2001, of the American Underground Construction Association (now the Underground Construction Association), an organization of professionals working to promote better understanding, development and use of underground facilities.

Founded in 1974, ITA has over 50 Member Nations and over 270 Affiliate Members. ITA’s Goals are to promote advances in the planning, design, construction and maintenance of tunnels.

John Reilly is an involved member of ITA and has been the Animateur (Chairman) of Working Group 20 “Urban Problems – Underground Solutions” and Animateur of Working Group 13 – “Direct and Indirect Advantages of Underground Structures”. As Past President of AUA, the official U.S. Representative to ITA, he is concerned with International Policies regarding planning, construction and use of undeground facilities.

ITA Working Group Number 20, with the topic “Urban Problems – Underground Solutions” was created in Sydney in 2002 with John Reilly as first Chairman. ITA invited the Association ACUUS to participate as a “Sister Organization” in this important activity, with representation in the Working Group at the Vice Animateur level. Additionally France and USA have formed National Groups on this topic and their representatives participated in the Working Group meetings in Amsterdam.

In 2002 A data questionnaire was sent to all ITA Member Nations, asking them to identify the urban problems that have been solved, or could have been solved, by the use of underground space or facilities. As a result of this questionnaire, 6 reports – of varying length – were received from France, USA, Russia, Sweden Japan and Germany. Short letters were received from Norway, Netherlands, Czech Republic and Bulgaria.

The Working Group is presently considering urban problems that are of interest to planners, engineers and political decision makers – as they consider new infrastructure projects in Urban Areas. At the same time, case studies are being made of projects that have used underground space to solve one or more of these urban problems. It is hoped that these projects will be sufficiently diverse to represent good examples of solutions to the set of urban problems.

At the ITA meeting in Singapore in May of 2004, the relationship between the urban problems and how they have been resolved by these projects was examined. In this way, it will be possible to show which urban problems have been resolved by specific projects. It is hoped that the list of projects will grow so that a comprehensive statement can be made on this question and that the project examples become a good source of documentation for new, possibly innovative, solutions to Urban Problems.

John relinquished the role of Animateur in 2004 but still attends meetings at the annual ITA Conferences. Updates to the WG can be found on the ITA website.

ITA Working Group 13“Direct and Indirect Advantages of Underground Structures.”

John Reilly was the final Animateur of WG13, which completed its work by finalizing a report on Underground Transit Systems and Metro Systems. Specific questions examined include direct and indirect economic benefits of underground transit systems and the effects of public policies, environmental, geographic and economic conditions.

The report of WG13 was published in Tunneling and Underground Space Technology, Vol. 19, No. 1, January 2004. It is available on the ITA website.

Summary of report findings and recommendations

Following collection of a substantial amount of data from 30 cities in 19 countries, representing the situation from 1995 – 1998 (with some later updates) on the question “Underground or above ground – making the choice for Urban Mass Transit Systems”, analysis of that data and deliberations on the issues raised, the International Tunnelling Association offers the following findings and recommendations:

Findings:

The decision on whether to place an urban mass transit system underground or aboveground is a complex planning, engineering, construction, urban design, economic and political decision.

In many cases – for example in the center areas of older cities – for functional, social, historic environmental and economic reasons there is no alternative to the choice of an underground alignment for new mass transit systems.

For many developing countries, the investment cost of a fixed guideway urban mass transit system is significant compared to the national or city economies. For urban mass transit systems developed or operated by private companies, return on investment is a critical issue.

The initial capital cost is only a part of the total long-term financial commitment. Costs include capital (including financing), operating, maintenance, security and rehabilitation.

Consideration of all costs – including capital, operating, maintenance, security and rehabilitation costs are necessary.

Consideration of all benefits – direct and indirect, short and long term – are necessary.

Long-term benefits such as increased economic activity and urban development potential are frequently not calculated in making the choice of whether to place an urban mass transit system underground or aboveground.

For the choice to be made well, both short and long term costs and short and long term benefits need to be objectively and comparatively considered.

Many aspects of the cost-benefit relationships are hard to quantify. Reference analyses and reports with the experience of other cities are very useful – particularly in the early stages of planning and design.

The problems of elevated alignments relate to availability of sufficient right-of-way, and the long-term environmental and real estate impact of elevated transit alignments. There is little quantitative data on which to base such decisions although there are many examples of older elevated railway alignments that have been removed due to public objections or to reverse urban blight.

In areas outside the city center, at-grade and elevated alignments offer the ability to construct greater lengths of transit system at the same initial capital cost or to lower the investment cost of a system of fixed size.

A cost ratio typically assumed for surface versus elevated and versus underground systems has been reported to be 1/3/6. Analysis of the data received from this questionnaire showed very large variations in cost ratios according to the particular circumstances of each city and existing infrastructure – which means that such rations are not very useful in practice. The median ratios from the data received for this report were approximately 1/2/4.5.

Working Group discussions confirmed that (with some exceptions) the relative costs of underground systems relative to surface and elevated systems are tending to narrow. This is particularly true in areas of high land value and as environmental restrictions on surface and elevated construction monetarize the differences in land and environmental impact. Better technology and productivity for underground construction methods are also helping to narrow this cost differential.

Underground construction costs are tending to fall with time, as technologies and productivity improve. However, the costs of underground transit systems may not reflect this due to the fact that higher standards of amenity and safety are being built into new underground systems, e.g. large volume public spaces, air conditioning systems, better surface finishes etc.

Recommendations:

The choice of underground versus aboveground for urban mass transit systems must be made by each city considering each area of the transit system, based on its own specific circumstances.

Few cities which have had Metro systems in use for a substantial time regret the choice to build that system and, in general, to place it underground near and adjacent to the city center.

The above statement, and the economic/cost environment which supports it, should be documented and publicized to assist decision-makers in making choices for new Metro systems.

Cities and transit agencies that undertake specific studies of the relative advantages and disadvantages of underground transit alignments, especially those including long-term cost/benefit information, are encouraged to publish their analyses and findings for the benefit of other decision makers around the world.

The critical decision between an underground and an aboveground alignment in many cases is strongly, if not completely, influenced by the issue of perceived high initial capital cost. This decision should, however, consider the benefits of increased long-term social and environmental improvements and beneficial economic development.

Representative decisions for specific mass transit systems should be documented and illustrated by reference to current and retrospective studies of typical projects (including those older than 20 years), considering all costs and benefits, real and perceived.

Estimates of changes in land value and perceptions in changes in environmental conditions close to alignments and, quantified estimates of all the benefits that have accrued to the region because of the particular project, would be of particular interest.

Examples of elevated vs. underground road alignments would also be pertinent.